1. In 75 seconds 400ml of oxygen diffuses through a glass tube. If It takes 25 seconds for 100 ml of a gas X to diffuse through the same tube under similar conditions, calculate the relative molecular mass of the gas X

b) mutualism

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these nuts

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary